[Solved] Image-Angle affecting direction in Space Rocks tutorial

I'm currently going through the space rocks tutorial and am creating the asteroid's behaviour.
The tutorial tells you to change the object's image_angle each step to create a rotating effect, so that it
doesn't affect the asteroid's actual direction value.

When testing this behaviour, the asteroids started to change their direction as well as the image_angle.

I copied the code from the finished project, where this problem doesn't occur, and pasted into my version and i still get the same behavior.
Why is the direction of my asteroid get changed when I'm changing its image_angle?

creation code:
sprite_index = choose(spr_asteroidSmall, spr_asteroidMedium, spr_asteroidLarge);
direction = irandom_range(0, 359);
image_angle = irandom_range(0, 359);
speed = 1;

Step event:
move_wrap(true, true, sprite_width / 2);
image_angle = image_angle + 1;